JP2018193587A - Method of producing metal product by electroforming - Google Patents

Abstract

To produce a metal product by performing electroforming only once, without a need for forming an electroconductive film or for carrying out conductive processing on the surface of a vanishing material.SOLUTION: First, a liquid mixture 14 of liquid rubber and a liquid hardener is poured into a container 13 containing a model 12 disposed thereinside to bury the model therein, and subsequently the liquid mixture is hardened to produce a rubber mold 16. Thereafter, the model is extracted from the rubber mold and an electroconductive vanishing material 18 is poured into a cavity 16a formed in the rubber mold and is hardened to produce an electroconductive vanishing model 19. Subsequently, the electroconductive vanishing model extracted from the rubber mold and electroforming metal are immersed in the electrolytic liquid present in an electrolytic tank, and an electric current is supplied to them to form a metal layer on the surface of the electroconductive vanishing model by electrodeposition. Further, the electroconductive vanishing model with a metal layer formed on the surface thereof is taken out of the electrolytic tank and is heated to cause the electroconductive vanishing model to vanish, thereby producing a metal product comprising a metal layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a metal product having a complicated shape such as a hollow metal pipe by electroforming.

  Conventionally, a conductive film is formed on the surface of a solder mold formed by adhering a solder, and the solder mold and the electroformed metal are placed in an electrolytic solution and the current flows through the solder mold. A method for producing a baking mold is disclosed, in which an electroformed metal is electrodeposited on the film to form a baking mold, and then the wax mold and the conductive film are removed to remove the baking mold (see, for example, Patent Document 1). . In this bread baking mold manufacturing method, the solder mold and the conductive film are melted by heat or chemical reaction, and the electrodeposited metal layer, that is, the bread baking mold is taken out.

  In this bread baking mold manufacturing method, a bread baking mold can be easily manufactured in a short time without using expensive male molds and female molds, so that the bread baking molds can be formed at low cost.

  On the other hand, a mold method for manufacturing a mold for resin molding having a fluid passage for cooling or heating by an electroforming method is disclosed (for example, see Patent Document 2). In this mold manufacturing method, first, an inner surface side electrodeposited metal layer is formed by electroforming on the surface of a master model having an outer shape equivalent to that of a molded product. Next, after forming a groove to be a fluid passage in the surface portion of the inner surface-side electrodeposited metal layer, the lossable material can be removed by chemical or physical means such as dissolution, vaporization, and combustion. Fill with. Next, the surface of the inner surface side electrodeposited metal layer is continuously subjected to electroforming, so that the outer surface side electrodeposited metal is covered with the disappearance material while covering the groove opening. Form a layer. Further, the disappearing material buried in the groove is removed by chemical or physical means. In addition, the surface of the master model is subjected to a conductive treatment in advance before electroforming. Further, as the disappearing material, wax or paraffin that can be removed by heating is used, and low melting point alloy solder, synthetic resin, natural resin, or the like can be used. Thereafter, a conductive treatment is performed on the surface of the extinguishing material in the groove as necessary.

  In the mold manufacturing method configured as described above, the electrodeposited metal layer is formed in two stages of the inner surface side electrodeposited metal layer and the outer surface side electrodeposited metal layer, and the groove formed in the inner surface side electrodeposited metal layer. Since a fluid passage was formed by embedding an extinguishing material that can be removed by chemical or physical means, a mold for resin molding having excellent surface transferability can be produced. The controllability is excellent, and the molding cycle of a molded product using this mold can be shortened.

JP 2000-279082 A (Claim 2, paragraphs [0010] and [0019], FIGS. 5 to 9) Japanese Patent Laying-Open No. 2014-205318 (Claim 1, paragraphs [0010], [0016], [0019], FIGS. 1 to 3)

  However, in the method for manufacturing a baking mold shown in the above-mentioned conventional patent document 1, a conductive film must be formed on the surface of the wax mold, and the conductive film is melted by a chemical reaction to take out the baking mold. There was a problem that the man-hour increased. In addition, the conventional baking method disclosed in Patent Document 1 has a problem in that only a baking die having a unidirectional surface on which a wax-type conductive film is formed can be produced. On the other hand, in the conventional mold manufacturing method disclosed in Patent Document 2, the surface of the master model and the surface of the extinguishing material in the groove must be subjected to conductive treatment, which increases the number of steps. It was. Further, in the mold manufacturing method disclosed in the above-mentioned conventional patent document 2, electroforming must be performed twice, and a groove to be a fluid passage is formed using a processing jig, a cutting tool, or the like. After that, the groove has to be filled with a disappearing material, which increases the number of steps.

  The first object of the present invention is to provide a method for producing a metal product by electroforming, in which it is not necessary to form a conductive film or conducting a conductive treatment on the surface of the disappearing material, and a metal product can be produced by a single electroforming process. It is to provide. The second object of the present invention is to provide a method for producing a metal product by electroforming, which can produce the entire surface of the metal product having a complicated shape.

  The first aspect of the present invention is that, as shown in FIGS. 1 and 2, a liquid mixture 14 of liquid rubber and a liquid curing agent is poured into a container 13 in which a model 12 is installed, or in a plurality of rubber blocks. The process of immersing the model in the liquid mixture 14 or in the rubber block by placing the model and applying heat and pressure, and curing the liquid mixture 14 in the container 13 or cooling the rubber block to form the rubber mold 16. A step of manufacturing, a step of taking out the model 12 from the rubber die 16 after taking out the rubber die 16 from the container 13, and forming a cavity 16a having a shape corresponding to the model 12 in the rubber die 16, and a cavity of the rubber die 16 A step of producing a conductive disappearance model 19 by injecting and curing a disappearance material 18 having conductivity into 16 a, and removing the conductive disappearance model 19 from the rubber mold 16. Between the step of immersing the conductive disappearance model 19 and the electroformed metal plate 21 in the electrolytic solution 23 in the electrolytic bath 22 and the current between the conductive disappearance model 19 and the electroformed metal plate 21 in the electrolytic solution 23. To form a metal layer 26 by electrodeposition on the surface of the conductive disappearance model 19, and to remove the conductive disappearance model 19 with the metal layer 26 formed on the surface from the electrolytic cell 22 and heat it. The manufacturing method by electroforming of the metal product including the process of producing the metal product 11 made of the metal layer 26 by eliminating 19.

  The second aspect of the present invention is an invention based on the first aspect, and as shown in FIG. 1, the heat resistance temperature of the rubber mold 16 is −40 to 150 ° C., and the conductive disappearance model 19 is a rubber. It is formed of a low melting point metal having a melting point of -19 to 98 ° C. lower than the melting point of the mold 16.

  The third aspect of the present invention is the invention based on the second aspect, wherein the low melting point metal is further selected from the group consisting of bismuth, lead, tin, indium, cadmium, thallium, gallium and antimony. It is the above alloy.

  In the manufacturing method by electroforming of a metal product according to the first aspect of the present invention, a conductive disappearance model is prepared by injecting a cured disappearance material into a rubber mold cavity and curing it. When a current is passed in the electrolytic solution between the model and the electroformed metal plate, a metal product composed of a metal layer by electrodeposition on the surface of the conductive disappearance model can be produced. As a result, it is not necessary to form a conductive coating or conducting a conductive treatment on the surface of the disappearing material, and a metal product can be produced by a single electroforming process. In addition, compared with a conventional bread baking mold manufacturing method that can only produce a bread baking mold having a unidirectional surface on which a solder-type conductive coating is formed, the present invention has a complicated shape metal product such as an irregularly shaped pipe. The entire surface can be manufactured.

  In the method for producing a metal product by electroforming according to the second aspect of the present invention, since the conductive disappearance model is formed of a low melting point metal having a melting point lower than the melting point of the rubber mold, the rubber mold does not melt. A conductive disappearance model can be produced by injecting and curing a disappearance material having conductivity into the cavity. In addition, by heating a conductive disappearance model having a metal layer formed on the surface by electroforming at a temperature not lower than the melting point of the conductive disappearance model and not higher than the melting point of the metal layer, the conductive disappearance model disappears. A metal product comprising a metal layer can be produced.

It is process drawing of the first half which shows the manufacturing procedure by electroforming of the metal product of embodiment of this invention. It is process drawing of the latter half which shows the manufacturing procedure by electroforming of the metal product.

  Next, an embodiment for carrying out the present invention will be described with reference to the drawings. As shown in FIG. 2 (c), the metal product 11 is a metal pipe whose center line is not two-dimensionally curved but complicated in three dimensions in this embodiment. The metal product 11 is formed of a metal that can be electroformed, such as copper, nickel, gold, or silver. In order to manufacture the metal product 11 by electroforming, first, the model 12 is buried by pouring a liquid mixture 14 of liquid rubber and a liquid curing agent into a container 13 in which the model 12 (FIG. 1A) is installed. Thereafter, the liquid mixture 14 in the container 13 is cured to produce a rubber mold 16 (FIG. 1B). Since this model 12 is formed in a cylindrical shape that is curved in a complicated manner with the shape corresponding to the inner surface of the metal pipe 11 that is the metal product 11 as the outer surface, using a 3D printer, acrylonitrile butadiene styrene resin is used. It is made of a material such as (ABS resin), polylactic acid resin (PLA resin), or acrylic resin. Reference numeral 17 in FIG. 1B denotes a support member that supports the model 12 in the container 13. Further, the space formed when the support member 17 is taken out from the rubber mold 16 together with the model 12 becomes a runner for flowing a lost material 18 having conductivity described later into the cavity 16a. The shape of the model may be a shape that cannot be molded by a general resin or metal injection molding method in addition to a complicatedly curved columnar shape. If the model has a relatively simple shape, the model may be produced by machining or the like without using a 3D printer.

  Examples of the liquid rubber include silicone rubber. When silicone rubber is used as the liquid rubber, a liquid curing agent for curing the liquid rubber is added. This liquid hardening | curing agent is added 5-10 mass% with respect to 100 mass% of silicone rubber. Here, the addition amount of the liquid curing agent is limited to the range of 5 to 10% by mass with respect to 100% by mass of the silicone rubber. This is because if it exceeds%, the cured rubber mold 16 is easily torn. The heat resistant temperature of the cured rubber mold is −40 to 150 ° C.

  In this embodiment, a rubber mold was produced by pouring a liquid mixture of liquid rubber and a liquid curing agent into a container in which a model was installed, but the model was placed in a plurality of rubber blocks, and a hot press was used. The rubber block may be softened by being applied to a heat vulcanizer called a machine, the model is buried in the rubber block, and then the rubber block is cooled to produce a rubber mold. In this case, the rubber block is formed of silicone rubber or the like called baked rubber, and the heat resistant temperature (maximum specification temperature) is 280 ° C. Moreover, it is preferable that vulcanization temperature is 120-150 degreeC. For example, the vulcanization time is set at a rate of 1 minute for a rubber mold thickness of 1 mm at about 120 ° C. Thereby, the rubber block is softened without melting, and the model can be buried in the rubber block without being damaged. Further, the plurality of rubber blocks are preferably a pair of rubber blocks.

Next, after the rubber mold 16 is taken out from the container 13, the model 12 is taken out from the rubber mold 16 and a cavity 16a having a shape corresponding to the model 12 is formed in the rubber mold 16 (FIG. 1C). When the model 12 is removed from the rubber mold 16, the support member 17 is also removed together with the model 12. As a result, a cavity 16 a having a shape corresponding to the model 12 and a runner 16 b having a shape corresponding to the support member 17 are formed in the rubber mold 16. Here, there are the following two methods for removing the model 12 from the rubber mold 16.
(1) The first method is a method of cutting the rubber mold 16 into a plurality of rubber pieces and taking out the model 12 and the support member 17 from the rubber mold 16. In this method, when the rubber mold 16 is restored by combining the plurality of rubber pieces, the plurality of rubber pieces are brought into close contact with each other, so that almost no parting line appears on the inner surface of the cavity 16a of the rubber mold 16 and the outer surface of the model 12 Can be faithfully transferred to the inner surface of the cavity 16 a of the rubber mold 16.
(2) The second method is a method of taking out the model 12 and the support member 17 from the bottom surface side of the support member 17 by elastically deforming the rubber mold 16. In this method, the model 12 can be removed from the rubber mold 16 without damaging the rubber mold 16, no parting line appears on the inner surface of the cavity 16 a of the rubber mold 16, and the outer surface of the model 12 is connected to the cavity 16 a of the rubber mold 16. Can be faithfully transferred to the inner surface.

Then, a conductive disappearance model 19 is produced by injecting and curing a disappearance material 18 having conductivity into the cavity 16a of the rubber mold 16 (FIG. 1 (d)). In order to inject the lost material 18 having conductivity into the cavity 16a of the rubber mold 16, the rubber mold 16 is turned upside down. As a result, the gate 16c, which is an inlet for the lost material 18 having conductivity, is positioned on the upper surface of the rubber mold 16. Further, when the rubber mold 16 is cut into a plurality of rubber pieces, the rubber mold 16 is reinserted into the container 13 or the outer peripheral surface of the rubber mold 16 is fixed to the jig so that the restored rubber mold 16 does not fall apart It is preferable to fix with (not shown). The conductive disappearance model 19 is preferably formed of a low melting point metal having a melting point of −19 to 98 ° C. lower than the heat resistance temperature of the rubber mold 16. Specifically, the low melting point metals are bismuth (Bi), lead (Pb), tin (Sn), indium (In), cadmium (Cd), thallium (Tl), gallium (Ga) and antimony (Sb). It is preferable that it is 3 or more types of alloys chosen from the group which consists of. More specifically, the low melting point metals include Rose's alloy, CerroSAFE, Wood's alloy, Field alloy, Cerrolow 136, Cerrolow 117, Bi-Pb. -Sn-In-Cd-Tl alloy, Galinstan, etc. are mentioned. The contents (mass%) and melting points of low melting point metals in these alloys are as follows.
(1) Rose's alloy: Bi: Pb: Sn = 50: 25: 25, melting point: 98 ° C.
(2) CerroSAFE: Bi: Pb: Sn: Cd = 42.5: 37.7: 11.3: 8.5, melting point: 74 ° C.
(3) Wood's alloy: Bi: Pb: Sn: Cd = 50: 26.7: 13.3: 10, melting point: 70 ° C.
(4) Field alloy: Bi: Sn: In = 32.5: 16.5: 51, melting point: 62 ° C.
(5) Cerrolow 136... Bi: Pb: Sn: In = 49: 18: 12: 21, melting point: 58.degree.
(6) Cerrolow 117: Bi: Pb: Sn: In: Cd = 44.7: 22.6: 8.3: 19.1: 5.3, melting point: 47.2 ° C.
(7) Bi-Pb-Sn-In-Cd-Tl alloy: Bi: Pb: Sn: In: Cd: Tl = 40.3: 22.2: 10.7: 17.7: 8.1: 1 1. Melting point: 41.5 ° C.
(8) Galinstan: Bi: Sn: In: Ga: Sb = less than 1.5: 9.5 to 10.5: 21 to 22:68 to 69: 1.5, melting point: −19 ° C. .
Here, the preferable melting point of the low melting point metal forming the conductive disappearance model 19 is limited to the range of −19 to 98 ° C. When there is no low melting point metal below −19 ° C., and the melting point exceeds 98 ° C. This is because the rubber mold 16 is melted before the conductive disappearance model 19 is melted. That is, when a low melting point metal in the above temperature range is used, the conductive disappearance model 19 is obtained by injecting and curing the disappearance material 18 having conductivity into the cavity 16a of the rubber mold 16 without melting the rubber mold 16. Can be produced. Of the low melting point alloys (1) to (8), the low melting point alloys (3) to (8) are eutectic.

  Next, after removing the conductive disappearance model 19 from the rubber mold 16 (FIGS. 1 (e) and 1 (f)), the conductive disappearance model 19 and the electroformed metal plate 21 are connected to the electrolytic solution 23 in the electrolytic cell 22. (Fig. 2 (a)). Here, in the conductive disappearance model 19 taken out from the rubber mold 16, the model sprue 24 solidified in the runner 16c is integrally formed with the conductive disappearance model 19 (FIG. 1 (e)). By cutting off the model sprue 24, the conductive disappearance model 19 is produced (FIG. 1 (f)). Further, the type of metal of the electroformed metal plate 21 immersed in the electrolytic solution 23 is an electroformed metal such as copper, nickel, gold, or silver that is electrodeposited on the surface of the conductive disappearance model 19. The electrolytic solution 23 is appropriately selected depending on the type of electroformed metal. For example, when the electroformed metal is copper, it is preferable to use an acidic copper sulfate bath, and when the electroformed metal is nickel, it is preferable to use a nickel sulfamate bath. Then, a current is passed between the conductive disappearance model 19 and the electroformed metal plate 21 in the electrolytic solution 23 to form a metal layer 26 by electrodeposition on the surface of the conductive disappearance model 19 (FIG. 2A). . Specifically, the electroformed metal plate 21 and the conductive disappearance model 19 are connected in a state where the electroformed metal plate 21 is connected to the positive pole of the DC power supply 27 and the conductive disappearance model 19 is connected to the negative pole of the DC power supply 27. A DC voltage of 2 to 5 V is applied between them. As a result, ionization (dissolution) of the electroformed metal occurs on the surface of the electroformed metal plate 21 (anode), and precipitation (electrodeposition) due to reduction of the electroformed metal occurs on the surface of the conductive disappearance model 19 (cathode). Thus, the metal layer 26 is formed on the surface of the conductive disappearance model 19.

  Further, the conductive disappearance model 19 having the metal layer 26 formed on the surface is taken out from the electrolytic cell 22 (FIG. 2 (b)), and the conductive disappearance model 19 is disappeared by heating to make a metal product made of the metal layer 26. 11 is produced (FIG. 2C). Here, before heating the conductive disappearance model 19 having the metal layer 26 formed on the surface, the electrodeposited metal layer 26 is cut off on the upper and lower surfaces of the conductive disappearance model 19 (FIG. 2B). . In this state, the conductive disappearance model 19 having the metal layer 26 formed on the surface is set to a predetermined temperature, that is, a temperature higher than the melting point of the conductive disappearance model 19 and lower than the melting point of the metal layer 26 (for example, 100 ° C.). When heated, the conductive layer 19 is melted and flows down from the cylindrical metal layer 26 without melting the metal layer 26, so that the hollow metal product 11 is completed. As a result, it is not necessary to form a conductive coating or conducting a conductive treatment on the surface of the disappearing material, and the metal product 11 can be produced by a single electroforming process.

  Since the hollow metal product 11 manufactured in this way is formed by electroforming (electrodeposition by electrolysis), the complicated shape of the model 12 can be precisely reproduced.

DESCRIPTION OF SYMBOLS 11 Metal product 12 Model 13 Container 14 Liquid mixture of liquid rubber and liquid hardening agent 16 Rubber mold 16a Cavity 18 Dissipative material with conductivity 19 Conductivity disappearance model 21 Electroformed metal plate 22 Electrolytic tank 23 Electrolytic solution 23 Electrolyte 26 Metal layer

Claims (3)

The model is placed in the liquid mixture or in the rubber block by pouring the liquid mixture of liquid rubber and liquid curing agent into the container in which the model is installed or by placing the model in a plurality of rubber blocks and applying heat and pressure. And the process of immersing in
Curing the liquid mixture in the container or cooling the rubber block to produce a rubber mold;
Removing the model from the rubber mold after removing the rubber mold from the container and forming a cavity having a shape corresponding to the model in the rubber mold;
Producing a conductive disappearance model by injecting and curing a disappearance material having conductivity into the rubber mold cavity; and
A step of immersing the conductive disappearance model and the electroformed metal in an electrolytic solution in an electrolytic cell after removing the conductive disappearance model from the rubber mold;
Forming a metal layer by electrodeposition on the surface of the conductive disappearance model by passing a current between the conductive disappearance model and the electroformed metal in the electrolyte; and
Removing a conductive disappearance model having the metal layer formed on the surface thereof from an electrolytic cell and heating to eliminate the conductive disappearance model to produce a metal product comprising the metal layer. By the manufacturing method.   2. The metal product according to claim 1, wherein the heat resistance temperature of the rubber mold is −40 to 150 ° C., and the conductive disappearance model is formed of a low melting point metal having a melting point −19 to 98 ° C. lower than the melting point of the rubber mold. Manufacturing method by electroforming.   3. The method for producing a metal product by electroforming according to claim 2, wherein the low melting point metal is at least three kinds of alloys selected from the group consisting of bismuth, lead, tin, indium, cadmium, thallium, gallium and antimony.

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